How does planting trees in urban areas improve air quality and reduce energy use?

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Explain why electric current cannot exist if a current doesn't have a voltage source.

Apositive charge moves in the direction of an electric field. which of the following statements are true? check all that apply. check all that apply. 1.the potential energy associated with the charge decreases. 2. the electric field does positive work on the charge. 3. the electric field does negative work on the charge. 4. the potential energy associated with the charge increases. 5. the electric field does not do any work on the charge. 6. the amount of work done on the charge cannot be determined without additional information.